System for calibrating the parallelism between the printing plane and the virtual plane on which the extruder of a 3d printer moves

An automatic method for calibrating the parallelism between a printing plane of a 3D printer and a virtual plane on which the extruder of said 3D printer moves, to align the printing plane with the virtual plane on which the extruder moves, the method comprising:

• 1) moving the printing head on a first rear central point (P-ZB) of the printing plane;
• 2) detecting the absolute coordinate (Offset P-ZB) of the first point (P-ZB);
• 3) moving the printing head on a second front side point (P-ZR) of the printing plane;
• 4) detecting the absolute coordinate (Offset P-ZR) of the second point (P-ZR);
• 5) moving the printing head on a third front side point (P-ZL) of the printing plane which is not aligned with the previous two points;
• 6) detecting the absolute coordinate (Offset P-ZL) of the third point (P-ZL);
• 7) operating a first actuator (A-ZR) for a movement equal to the difference between the absolute coordinates of the first and second point (Offset ZB-Offset ZR);
• 8) operating a second actuator (A-ZL) for a movement equal to the difference between the absolute coordinates of the first and third point (Offset ZB-Offset ZL);
• 9) verifying if the extent of at least one of the two movements referred to in steps 7) and 8) is greater than 0.08 mm:
• if so, the procedure is repeated from step 1) otherwise it may advance to the following step;
• 10) end of method.